1. Field of the Invention
This invention relates generally to an apparatus for and method of steam treating of fodder, for example animal fodder (such as grasses, herbaceous legumes, tree legumes, silage and crop residues), which is typically in baled form, which is intended to include bales as well as retaining nets, baskets or similar receptacles.
2. Background of the Related Art
The purpose of steam treating is to kill mesophilic and thermophilic mould spores that are either attached to the fodder or detach when disturbed and become airborne. These airborne particles are commonly assumed as dust spores, together with any living organisms and can include insects and the like. The purpose therefore of treating the fodder is to kill all the aforesaid prior to the fodder being fed to livestock; thus reducing the risks of creating or aggravating respiratory problems, infections and allergies from such or similar organisms. The problem associated with respiratory conditions, infections and allergies applies to, both livestock being fed as well as humans handling the fodder or when preparing and feeding the fodder to livestock.
Most forms of livestock are fed predominantly on conserved fodder from manmade bales; in their whole, in part, or detached from the whole bale and inserted in a receptacle such as a net or basket.
Fodder is one of the cheapest and most widely available natural forms of feeding livestock and provides most of the nutrients required. When fodder, such as grasses and crop residues, is cut, it is usually compressed into bales for ease of storage and manoeuvrability. All fodder contains leaf shatter, soil, mesophilic moulds, plant particles, fragments of sundry inorganic materials, bacteria, fungi and fungal spores, insects, and other organisms in varying amounts. When the fodder has been cut and stored additional organisms (thermophilic actinomycetes) are also present. All of this matter is generally classified as dust. Much of this dust is present in particles of less than 5 microns in diameter (respirable particles) and these particles can cause an allergic reaction within some livestock (e.g. horses and certain goat species). The allergic reaction is precipitated by a hypersensitivity to the respirable particles which leads to airway inflammation, bronchoconstriction and accumulation of mucoid secretion in the animal's airways.
Clinical signs such as coughing and reduced capacity for exercise are persistent. These conditions include the well known Recurrent Airway Obstruction (RAO)—also known as Chronic Obstructive Pulmonary Disorder (COPD)—and are responsible for a significant loss of revenue in terms of days in training and reduced performance. Moreover these respirable particles are the cause of the debilitating condition in humans known as Farmers Lung, as well as more common hayfevers. Some livestock owners soak their fodder, such as hay, to reduce the number of airborne particles released during feeding.
However, the initial handling of the material usually results in the dust becoming airborne and present in the atmosphere exposing animals and humans alike to hazardous respirable particles. While soaking fodder has proved effective in reducing respirable particle numbers, it does not kill the fungi and bacteria present and thus ingestion of these pathogens still occurs and can lead to other associated problems, particularly in breeding livestock. Furthermore soaking has been scientifically proven to leach some of the nutritional content from the fodder; and produces a post-soak liquid that has a high biological oxygen demand classifying it as an environmental pollutant.
Examples of steam treating fodder are described in UK Patent Application GB 2 338 167 A (Meech & Davis).
Another type of fodder steam treatment system is described in UK Patent Application GB 2 387 311 A (Bottomley).
Although the aforementioned systems operated with a reasonable degree of success they suffered from a number of drawbacks.
Another type of hay steamer is made and sold by Happy Horse Products limited and includes a conventional steam generator which delivers steam, via a lance, into loosely packed fodder which is contained in a bag. In the event that the bag is waterproof steam condenses in the bag with the result that there is a build up of hot water condensate in the bag and the aforementioned risk of leaching of nutrients from the fodder. In the event that the bag is permeable, a disadvantage of this system is that fodder has to be handled twice. Firstly it needs to be removed from a bale or hay rick and placed in the bag; then it has to be removed from the bag for feeding.